Hori Hori WIP

[RyanW]

I was over at BF Member Ursusrubrum's House working on some kydex sheaths for some finished knives. He is a great sheathmaker and likes to trade sheath work for custom knives. He mentioned he was an archeologist and would like to see someone make a Custom Hori - Hori. I was unfamiliar with the tool so he drew me a quick photo of what it looks like.

When I got home I did some online research This is what I found: Hori-Hori (Dig-Dig or Digging-Digging) is a Japanese tool used often by bonzai "Masters" and simple gardeners alike, Seems Archeologist like them too. I found a few different models available for purchase online, some better than others. They are inexpensive ($20 - $30) and cheaply built for the most part. Jason wanted a full tang version that he could use while working in the yard or in the field. I was game to give it a shot, I knew it would be a little rough as a new maker.

I started with a piece of 1/4" x 1.5" x 12" Aldo 1084. I drew up a dagger looking design that was symmetrical on both sides to enable Right and Left hand Use since I was planning on leaving one side completely flat and the other side Hollow ground down the middle and chisel grind on both edges (Think Blood Groove).

Here is the Original Design

A few concerns that I had:

1. The hollow grind will be too wide since I only had a 10" contact wheel
2. I had done Serrations on blades before but never made a functional Saw edge, the plan was to land somewhere in the middle.
3. This tool will be used for Digging, Sawing and Cutting. In my mind that is a hard combination get the right HT on. The edges needed to be relatively hard to maintain an edge after being plunged into the earth time and time again. It's entire blade needed to be able to flex (not Break) but still not bend when digging.

I marked out the design on the steel, drilled the pin and weight reduction holes in the tang, profiled and flat ground the blank. (No photos of this process... Sorry)

I started with the hollow grind on one side it turned out great IMO. I went right down the middle edge to edge, the center thickness (thinnest point) sat right around 1/8" which Jason and I thought was spot on....
Hollow Grind:

I then started grinding the flat chisel grinds on the same side as the hollow grind. I kept them even and straight and went approx 1/4" in from both edges. I quickly realized that I was correct in my earlier concern (#1 above) The hollow grind was too shallow due to the 10" wheel. As the chisel grinds came close together (in the center of the blade) the hollow grind started to look flat. I contacted Jason for input (it's his blade after all), He said "Why don't you turn the chisel grind into a dagger grind, flip it over and hollow grind the other side so it is like a spoon" Crazy... I thought. After an hour or so of holding the blade and contemplating I realized it was the only option. I flipped the blade over and started grinding. I LOVED IT! The blade was now thinner than I had planned so the bending/snapping blade became an even bigger concern. I cut in some saw teeth, filing every other one down in the opposite direction of the flat grinds.

Now to address the HT and Tempering: Jason and I thought it would definitely need a differential heat treat to keep the edge hard and the center soft, clay hardening was the only option IMO. That is today's project, I will keep you posted.

Thanks for Looking, Comments welcome and Encouraged!
Ryan W.

 

[RyanW]

Saving for final Photos....

 

[koyote]

Awesome job!

I've been sort of avoiding doing a hori hori for a long time because I don't really want to hollow grind it. I'm really glad to see a custom one being done!

And it's a really excellent one, too.

 

[Daniel Fairly Knives]

I can't wait to see how this one turns out!

 

[Dabling]

I really love this "tool". Once I get the finished product, I will put it to use and provide a long term experience report to go along with this thread.

 

[Lorien]

Ryan-:thumbup:

 

[RyanW]

Awesome job!
I've been sort of avoiding doing a hori hori for a long time because I don't really want to hollow grind it. I'm really glad to see a custom one being done!

And it's a really excellent one, too.

Thanks Christof! I actually saw some of your Hori posts here BF (Wow that sounds wrong!) during my research.

I can't wait to see how this one turns out!

Daniel you should be proud of me, this was my first official chisel grind as well!

I really love this "tool". Once I get the finished product, I will put it to use and provide a long term experience report to go along with this thread.

I look forward to it! But if it breaks or bends excessively just bury it in the ground and let some other archeologist find it years later... Scratch off my makers mark first please!

Ryan-:thumbup:

Thanks for the helpful input!

 

[RyanW]

I got the HT done last night, 3 thermal cycles then prior to quench the clay fell off. Let it cool down, I cleaned it up a bit re-applied the clay then SUCCESS! Unfortunately I was too focused and forgot to take photos of the clay on the blade but I took some photos after HT. You can see where the clay was.

The necker in this photo is also for Jason W2 (Hopefully Hamon under there)

They are tempering in the oven right now for the second cycle. I will try to get the handle worked up tonight.
Thanks for your comments, this has been a fun one for me!
Ryan

 

[Lorien]

man that is cool!

 

[Mitchell Knives]

That is very cool! Never heard of those before.

It looks like the clay stayed put; should be a nice hamon!

 

[Aldo Bruno]

Ryan, I saw the thread yesterday and was going to mention that, because of the shape of it that it might warp. Did you have any trouble with it?

 

[Mike Davis]

Ryan, that is sick bro! You are defininately a talented fella!

 

[RyanW]

Thanks Lorien, Johnathan and Mike The clay stayed put and I will be bringing out the Hamon on the little necker (W2) but won't mess with the Hori (1084) and a worker...

Aldo, I did get a little bit of warping towards the hollow grind side. I corrected a little bit of it and left a very slight curve cause I felt it added to the Spoon/Digging aspect of the Tool. I have the handles glued up and will add that to this WIP a little later today.

 

[ScottRoush]

This is great.... Very similar shape to some ken, umabari, tsurugi and other esoteric Japanese blades I've been investigating.

I'm gonna have to steal this idea. My wife just got here Christmas present!

 

[RyanW]

This is great.... Very similar shape to some ken, umabari, tsurugi and other esoteric Japanese blades I've been investigating.

I'm gonna have to steal this idea. My wife just got here Christmas present!

Cool. Make sure you let us have a look at it when you get one made up!

 

[RyanW]

UPDATE:

I have been working on this over the last few days, I just wasn't able to get these photos ready... There are quite a few so DIAL UP BEWARE!
Here is the blade right out of HT ready for tempering, you can see where the clay was on the center of the blade.

Materials: Jason wanted something that was easy to see, So I went with something that looks just like Dirt . I am going with Hunter Orange Liners and bolster separator. the Micarta is from "Made in the Shade" (BF: "fod") they are Canvas Micarta that GLOW IN THE DARK! so if you lose this Jason you need to wait until night to find it! LOL

Lining up the Scales: When I do the Bolster sections it is critical to get both scales lined up. I do things a little different in this step when I don't need to line them up.

Drilling Pin Holes: I make sure my Drill press is square and the scales are level. I drill through the knife to assure propper alignment. in this case I am drilling with 1/8" and 1/4" Bits. I go slow and am careful not to over heat the bit, to avoid burning the scale material.

Reaming the Holes: Then I Ream out the holes to make room for glue and so pins don't bind when assembling, In this case I am using Metric bits #30 (slightly bigger than 1/8") and #F (slightly bigger than 1/4") I drill from the bottom side of each scale in case I am off a little it will not show like it would if drilling on the other side.

Marking the Back side of each Scale: This step is done for two reasons; I do all my drilling with the scales still square so the vice will hold securely. I don't want to drill the glue holes (see below) without knowing where the knife Tang ends. and I use these lines when cutting scales on band saw.

Drill glue holes: I drill holes through the liners to help the glue not all squeeze out when clamped. I make sure to get contact with the thicker scale material to increase strength.

Cut out Scales: I use my band saw to cut out the scales, I cut on the outside edge of my mark to allow the glue to pool between the scales. This helps glue fill any small voids between the Tang and liners.

Bolster / Ricasso Fit: I Pre assemble the scales so that I can mark the scales so that they will sit where I want them on the ricasso

Keep Checking to make sure it is where you want it... Still needs to come back a little more.

when I have the bolsters where I want them, I square them up together and sand to final grit before attaching to the blade.

Epoxy: I then cut pins to length, roughen all surfaces with sandpaper. I then pre assemble the scales just like I will when I have them epoxied up. This will save a lot of headaches. I then acetone all items that will be glued (Scales, Pins, Knife Tang) to remove Oil and dirt

I then apply the Acraglas epoxy on both scales, making sure air bubbles are removed from each hole in the liners. I apply epoxy on the end of the pins and slide them into their holes spinning and moving up and down to assure glue is moved through the entire hole.

I then slide the Tang onto the pins and fill the weight reducing holes in the tang. I also add a little glue around the base of each pin to fill the small bevels in the tang.

I then slide the other scale (Already Epoxied up) over the pins and clamp together. I don't want to press all the glue out but still want a tight fit. the small holes will help assure glue will remain in contact with the tang and scale.

Using acetone, paper towel, Q-tip and wood toothpick to clean any glue away from where the Scale bolster meets the ricasso. I don't want to be scratching the ricasso up trying to remove dried epoxy. This is the same reason I do the final sand here before gluing up.

I wasn't going to be this detailed but figured I had the photos so why not... This is just how I do it, there are MANY other ways. If you have any suggestions or questions I would love to hear them!
... Ryan

 

[RyanW]

Another update:

The Hori was clamped up for 24 hrs. to allow the Acraglas Epoxy to cure to full strength. I have cleaned up the excess on the sides of the tang. as you can see fit is pretty good, I added a slight Taper in the tang to reduce a little of the weight in the handle.

Here is the "Square" scale side:

Now time to shape the handle so it is super comfy in the hand. I plan on leaving it a little fatter that the usual Knife scales I do. that should help with digging and hard use for extended periods.

I Should have her all cleaned up Tomorrow.

 

[Mitchell Knives]

I really like what you did with the liners and scales; I may have to try that!

 

[Dabling]

That is so bas a$$! I love it! I can't wait!

 

[ERIK KNIVES]

Looking great, Ryan. Very inspired stuff going on here.